Part of my concern is: judging a resume is fine, since an applicant is explicitly submitting this. But rejecting based on things done for fun and publicly shown seems 'unfair'. (It's 'unfair' since I'll be judged right now for crap I haven't glanced at for 5 years or whatever, and haven't maintained to the best of my professional ability).

But part of why I consider it arbitrary is it's easy to come up with contradictory criteria, each of which might make sense. (-1 for using latest technology on a personal website, since it shows they buy into hype/resume-driven-development. -1 for not using the latest technology, since it shows they don't know the tools of the trade). I think this bleeds from trying to judge someone's professional capabilities as part of a team, from something produced in their spare time.